1. Field of the Invention
The present disclosure relates to devices and methods useful in medical diagnostics and treatments, in particular diagnostics and treatments performed in a lumen of a body, for example phototherapeutic treatments that illuminate a portion of the lumen.
2. Description of the Related Art
In recent years, much research has been devoted to phototherapeutic, and especially photoreactive therapies. These therapies typically involve the excitation of a class of photo-reactive compounds (i.e., “photosensitizers”) that kill diseased or undesirable tissue. The photosensitizers are typically activated by illumination with at least one specific wavelength of light (i.e., excitation wavelength) and are used in photodynamic therapy (PDT). Various wavelengths may be suitable depending on the specific photosensitizer, for example wavelengths of electromagnetic radiation in the visible, infrared, and/or ultraviolet portions of the electromagnetic spectrum may be suitable.
Light sources such as lasers, emitting the appropriate excitation wavelength, are typically used to activate the photosensitizers to treat targeted tissue in a number of eye, cardiac, oncological and other disease conditions. For example, in age related macular degeneration (AMD), glaucoma, and/or diabetic retinopathy (DR), photosensitizers may be used to inhibit formation or retard disease progression such as commonly indicated by rapidly uncontrolled vascular growth (i.e., “neovascularization”) within diseased eye tissue and the associated sub-retinal fluid concentration.
The two important and related components of a photoreactive treatment system are the photosensitizer and the excitation light source and apparatus for supplying the light appropriately to targeted tissue. Conventional approaches to PDT are challenged by requirements of light exposure of desired intensities, duration, shape, and timing when photosensitizers are present in the diseased tissue. Inaccurately generated illumination, such as misdirected or misshaped illumination, could have unintended affects. Accordingly, an appropriate medical apparatus for providing illumination in a lumen of a body that is well suited to the organ being treated may be a factor in successful treatment.